The invention relates generally to an electronic transceiver assembly, and more particularly, to a receptacle which is mounted on a circuit board and a transceiver module pluggable into the receptacle.
Various types of fiber optic and copper based transceivers that permit communication between electronic host equipment and external devices are known. These transceivers may be incorporated into modules that can be pluggably connected to the host equipment to provide flexibility in system configuration. The modules are constructed according to various standards for size and compatibility, one standard being the Small Form-factor Pluggable (SFP) module standard.
The SFP module is plugged into a receptacle that is mounted on a circuit board within the host equipment. The receptacle includes an elongated guide frame, or cage, having a front that is open to an interior space, and an electrical connector disposed at a rear of the cage within the interior space. Both the connector and the guide frame are electrically and mechanically connected to the circuit board, and when an SFP module is plugged into a receptacle it is electrically and mechanically connected to the circuit board as well. Conventional SFP modules and receptacles perform satisfactorily carrying data signals at rates up to 2.5 gigabits per second (Gbps).
A standard currently in development for a next generation of SFP modules, presently being called the XFP standard, calls for the transceiver modules to carry data signals at rates up to 10 Gbps. The transceiver modules will encounter several problems at the increased data rate not experienced previously. One problem is that the transceiver modules and the surrounding circuitry will generate significantly greater quantities of heat to be removed in order for the electronic components to survive long term. Another problem is that the transceiver modules will generate increased quantities of electro-magnetic (EM) energy at very short wavelengths. As the EM energy at the short wavelengths increases, the potential exists for more EM energy to pass through gaps in the shielding of the receptacle or guide frame. As more EM energy is accepted through the receptacle, the data signals conveyed by adjacent transceiver modules experience more EM interference (EMI). It is desirable to shield or isolate the data signals from EMI to the extent practical.
Further, conventional transceiver module assemblies include latch mechanisms to secure the transceiver module in the receptacle and to eject the transceiver module from the receptacle. It is desirable to provide a latch mechanism that is reliable, secure and robust.
There is a need to improve the design of a pluggable electronic module and receptacle in order to overcome present deficiencies and anticipated problems, among other things, due to higher data rates.
In accordance with an exemplary embodiment of the invention, a receptacle assembly comprises a guide frame having top, bottom and side walls joined to form an interior cavity configured to receive an electrical module. One of the top, bottom and side walls has an opening therethrough, and a heat sink is mounted over the opening. The heat sink has an engagement surface located proximate the interior cavity of the guide frame, and the engagement surface of the heat sink is configured to physically contact a module when installed in the interior cavity.
In accordance with another exemplary embodiment of the invention, the receptacle is a transceiver receptacle assembly. The assembly comprises a guide frame having top, bottom and side walls joined to form an interior cavity that is configured to receive a transceiver. One of the top, bottom and side walls has an opening therethrough, and a heat sink is mounted over the opening. The heat sink has an engagement surface located proximate the interior cavity of the guide frame, and the engagement surface of the heat sink is configured to physically contact the transceiver when installed in the interior cavity.
In an exemplary embodiment, the opening is in the top wall of the guide frame, and the bottom wall of the guide frame is configured to be mounted to a circuit board. The top wall of the guide frame includes front, rear and opposed lateral portions that define a perimeter of the opening and that support the heat sink when mounted over the opening. A retention tab is formed on one of the side walls of the guide frame, and the retention tab engages a heat sink clip retaining the heat sink on the guide frame. The heat sink includes an engagement surface which is stepped to extend into an interior cavity of the guide frame. A spring member is secured over the heat sink, and the spring member flexes to permit the heat sink to move outward away from the guide frame when a module assembly is inserted. The spring member exerts a desired force against the heat sink to facilitate thermal transfer from the module assembly.